Hard to say.
If yuy were going from the MMG's to the 1.6, then I'd say that it was a tremendous step-up in volume levels and bass (relatively speaking), but I don't think it will be that great fom the 12's. It willbe an improvement, though, maybe not of the same magnitude.
And, maybe I missed something, but i don't see your system listed. Lotsa clean power is the key to a happy 1.6.